Process of treating animal hides or skins.



`Nmshazf. PATEN'TBD SBPT.29,1903.

G.D.BURT0N.

PROCESS 0F TRBATING ANIMAL HIDES OR'SKINS.

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N0.7s9,s25. PATENTYBDSEPT. 29, 1903.A

' G.D.BURT0N.

PRUESS OP TREATING ANIMAL HIDES 0B. SKINS.

.APPLICATION FILED NOV. 8 1898,. BENBWEDFEB. 25, 1903.

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atented September 29, 190;

PATENT Finca.

- cannon n. snaren, or BosTcN, MASSACHUSETTS.

PROCESS OFfTREATI'l-NG` ANIMAL HIDES OR SKINS;

SPECIFICATION forming part of Letters jPatent'No. 739,825; dated September 29, 1903; Application nea nannte; s. isos. 'massif-Bist@ ze. i963. serai nq. 145,096. un Specimens.)

To all whom it may concern: f

Beit known that I, GEORGE DEXTER Bua- TON, a citizen of the United States of America,

residing in Boston, in the county of Suffolk,

s esses of Treating Animal'Hides Vor Skins, of

` which the following is a specification.

circulation of the solution.

This invention relates to the art of unhairing, tanning, or otherwise treating hides or skins by subjecting them to the action of a suitable electrolytic solution and passing an electric current through said solution ,in which the hides or skins are placed.

The object of the invention is to facilitate the passage of the electric current and the Figure l of the .accompanying drawings represents a longitudinal vertical section of' an apparatus for carrying out this process.

Fig. 2 represents a transversesectionthereof,

Similar reference-numerals indicate corresponding parts in both the igures.

A suitable vat or tanklO, constructed of any suitable material, contains the electrolytic solution, such as any suitable unhairing solution or any suitable tanning solution. This tank is preferably about seven feet long, ve feet deep, and four feet Wide. A positive electrode 2O is disposed in the tank, preferably near one end thereof, and a negativel electrode 30 is also disposed in the tank, preferably near the other end thereof. These electrodes are preferably composed of material which will neither dissolve nor disintegrate by the action of the elcctrolytic solution. They are in the form of plates suspended transversely across the vat. The positive electrode 2O is connected with the positive source ofelectricity by a cond uctor 40, and the negative electrode 30 is connected with the negative pole of the electric source by a conductor 50. Ascreen 60,preferablycomposed of wood or any other suitable non-conductive perforated material, is disposed transversely of the tank in front of the positive electrode- 20, and a similar screen 70 is disposed transversely of the tank in front of themegative electrode 30. The screen is provided near its top with a transverse bar 6l, and the screen is provided near its top with a transverse bar 71. A series of rods S0 are disposed longitudinallyof the tank below the normal level of the solution therein.v These rods are supported attheir opposite ends on the bars Gland 7l. The skins 90 are suspended on 4these,longitudinal rods, a skin being folded .overeachrod and depending on opposite sides thereof in the solution. The rods are disposed-apart from Veach other sufficiently to permit a free circulation of the'liquid between each hide or skin and are of sufficient thick- -ness to allow such circulation between-the folds of each hide or skin, and the disposition of the rodslongitudinally of the tank with their ends toward the electrodes permits the free circulation of the current between the dependentl folds of the hides or skins. The skins are' v at its lower end. The outer end of this pipe is connected with an air-forcing apparatus 110, of any suitable form. By this means air may be forced into the solution in the tank and cause the circulation thereof. The air so introduced not only causes a circulation of the solution or agitation thereof, but also aerates and cleanses the solution.

In carrying out this process by the use of this apparatus the hides or skins, preferably whole, are folded and hung over the several suspension-rods 80, in which case they are totally submerged by the solution, which for unhairing maybe any suitable solution known to the art for that purpose and for tanning any suitable tanning solution. A good unhairing solutionv consists of quicklime, red sulfid of arsenic, and water in the proportions of seventy gallons of Waterto ten pounds of quickliine and one pound of red suld ofxarsenic. The hides. or skins are preferably soaked in fresh Watervfor, say, twenty-four hours before subjection to this treatment. Any current of electricity of from six to five hundred volts and from five to live hundred amperes, according to the size of the tank 'and quantity of the solution and thev number of skins in the solution, is passed through the solution in which the hides or skins are suspended. This current has a tendency to set up an electrolytic action in the solution containing the hides or skins which causes the destruction of all germs therein, at the same time preserving the gelatin matter in the hides or skins. The current has free access to the'hide or skin surfaces, as also has the solution. The hides or skins may be subjected to this action until the hair-cells become sufficiently softened to allow the hairl to slip. I have found that a .treatment of thirty minutes suftices in some `trolyzed tanning solution, the current being of such a volume as to open the pores and permit a free circulation of the solution around them, causing a quick penetration of the tanning material and a hardening of the gelatinous matter, thereby preserving the gelatin in the hides or skins so treated.

Any suitable agitating means may be used; but the air-current is preferable, as it tends to purify the solution.

purifying the unhairing or tanning solution, I Wish to reserve the right to use any suitable gas for this purpose or a combination of gases.

A good tanning solution may consist of extract of hemlock-bark, starting the tanning process with a one-and-one-half-degree tanning liquor, barkometer test. This liquor is strengthened from time to time as the hides or skins absorb the tanning material until a gravity of about 14", barkometer test, is obv tained, when the skins will be found to be tanned. I have also used gambia, sumac, qnebracho 4and palmetto, oak, and other eX- tracts and obtained excellent results, starting the tanning process with about a one-degree liquor and completing the process with about a thirteen-degree liquor, barkometer test, when the above-mentioned extracts are used. I have sometimes added extract of logwood to the above tanning extracts for the Where I use thev -word air for agitating, circulating, and

tanks, the quantity of solution, and the number of hides or skins vbeing treated. This drenching process purifies the skin or hide and has a tendency to counteract the lime and plumps the skin or hide to a high degree. This process completed, the hides or skins may be again Washed in Water and are then ready to proceed with the tanning process. This treatment takes the place of what is known as bating in the tanning art with such material or substance as pigeon, dog, or

hen manure. For such skins as sheep, calf, kangaroo, and the like the above-described process of bating is used with very satisfactory results.

Any suitable electrodes may be used; but I obtain the best results by using one copper electrode and one lead electrode and by connecting the positive pole to the lead plate.

While I obtain the best results by placing the skins hair sides to each other, fairly good results are obtained by reversing the skins and placing the flesh sides to each other, and this specification is intended to cover either method. v

I claim as my invention- The process of treating animal hides or skins, which consists in suspending them in an electrolytic unhairing solution, subjecting them to the action of said solution and a current of electricity passed therethrough in lines parallel with the skins, said current being of sufficient volume to, open the pores of the hides or skins andincrease the action of the solution, and passing a current of air through said solution duringgthe passage of the eleotric current.

i encontraron.

Witnesses:

E. FrPHILIPsoN, ALBERT G. Y. MACADAM.

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